Table 1:

Baseline characteristics of 610 979 patients, by hospital harm status

CharacteristicNo. (%) of patients*Standardized difference
Hospital harm
n = 36 004
No hospital harm
n = 574 975
Age, yr, mean ± SD64.88 ± 19.8355.94 ± 21.020.44
Sex, female20 282 (56.3)350 975 (61.0)0.10
Neighbourhood income quintile
 Q1 (lowest)8571 (23.8)136 070 (23.7)0.00
 Q27972 (22.1)121 293 (21.1)0.03
 Q37150 (19.9)113 086 (19.7)0.00
 Q46231 (17.3)104 643 (18.2)0.02
 Q5 (highest)6015 (16.7)98 954 (17.2)0.01
Rural residence4034 (11.2)72 331 (12.6)0.04
No. of chronic conditions
 011 288 (31.4)129 606 (22.5)0.20
 13170 (8.8)91 936 (16.0)0.22
 23441 (9.6)88 306 (15.4)0.18
 33959 (11.0)79 057 (13.7)0.08
 44152 (11.5)63 977 (11.1)0.01
 ≥ 59994 (27.8)122 093 (21.2)0.15
Major clinical category, intervention18 256 (50.7)224 466 (39.0)0.24
Hospital Frailty Risk Score29
 Low risk (< 5)29 186(81.1)564 046 (98.1)0.58
 Intermediate (5–15)/high risk (> 15)6818 (18.9)10 929 (1.9)0.58
Teaching hospital14 844 (41.2)176 176 (30.6)0.22
Postadmission conditions, yes47 025 (8.2)
PCE category
 Pregnancy4524 (12.6)117 361 (20.4)0.21
 Trauma6175 (17.2)37 774 (6.6)0.33
 Mental health229 (0.6)38 404 (6.7)0.33
 Cancer4284 (11.9)34 153 (5.9)0.21
 Renal425 (1.2)4314 (0.7)0.04
 Planned surgical6080 (16.9)104 131 (18.1)0.03
 Planned medical183 (0.5)5359 (0.9)0.05
 Unplanned surgical5237 (14.5)45 212 (7.9)0.21
 Unplanned medical8867 (24.6)188 267 (32.7)0.18
Harm category
 Health care– or medication-associated conditions18 027 (50.1)
 Health care–associated infections13 328 (37.0)
 Patient accidents967 (2.7)
 Procedure-associated conditions9819 (27.3)
No. of hospital admissions within 1 yr before index admission, mean ± SD0.30 ± 0.820.22 ± 0.700.11
No. of ED visits within 1 yr before index admission, mean ± SD1.30 ± 2.361.31 ± 2.990.01
  • Note: ED = emergency department, PCE = person-centred episodes of care, SD = standard deviation.

  • * Unless stated otherwise.

  • International Statistical Classification of Diseases and Related Health Problems, 10th Revision, Canada diagnosis codes are used to categorize patients into major clinical categories. These broad categories are based on the most responsible diagnosis code. This diagnosis is the one determined to have been responsible for the greatest portion of the patient’s length of stay. Major clinical categories are divided into 2 partitions: intervention and diagnosis.

  • Because of small cell counts in those deemed high risk based on Hospital Frailty Risk Score, intermediate and high-risk groups were combined.